#include <iostream>
using namespace std;

typedef struct _Node{
    int data;
    struct _Node *next;
}node_t;

int create_node(node_t *&p, int value){
    p = (node_t *)malloc(sizeof(node_t));
    p->data = value;
    p->next = nullptr;
    return 0;
}

int main(int argc, const char *argv[]){
    node_t *phead = nullptr;
    create_node(phead, -1);
    cout << phead << endl; // 非NULL
    cout << phead->data << endl; // -1
    return 0;
}